That accusation, he said, "one of the most dishonest and reprehensible charges ever aired in this city."
"Some of the most irresponsible comments have, of course, come from politicians who actually voted in favor of authorizing force against Saddam Hussein," Cheney told the Frontiers of Freedom Institute, a conservative policy group.
Democrats shot back immediately, with the party's 2004 presidential nominee, Sen. John Kerry of Massachusetts, saying "it is hard to name a government official with less credibility on Iraq" than Cheney.
Cheney's speech was part of a GOP effort to push back against criticism on Iraq.
President Bush has made two speeches in recent days that painted Democrats as hypocrites for criticizing the Iraq war after earlier supporting the idea that Saddam should go.
On Tuesday, Defense Secretary Donald H. Rumsfeld singled out Democrats, including President Clinton and his secretary of state, Madeleine Albright, who had depicted Saddam as a threat because of weapons of mass destruction.
The Republican National Committee posted on its Web site a video compilation of past statements by prominent Democrats — including several 2008 presidential hopefuls — who supported a hard line against Saddam.
"These are elected officials who had access to the intelligence, and were free to draw their own conclusions. They arrived at the same judgment about Iraq's capabilities and intentions that was made by this administration and by the previous administration," Cheney said.
He said there was "broad-based, bipartisan agreement" that Saddam was a threat, had violated U.N. Security Council resolution and had banned weapons.
Senate Minority Leader Harry Reid, D-Nev., said Cheney was "playing politics like he's in the middle of a presidential campaign."
"I would urge the members of the Bush administration to stop trying to resurrect their political standing by lashing out at their critics," he said. "Instead, they need to focus on the job at hand, giving our troops a strategy for success in Iraq."
Democrats have said they got their information on U.S. intelligence assessments about Saddam's government from the administration. They have suggested that top administration figures — including Cheney, a staunch advocate of toppling Saddam — manipulated that intelligence to make a stronger case for invasion.
In October 2002, the Senate voted 77 to 23 to give Bush the authority to invade Iraq. The House approved the measure on a 296-133 vote.
In the Senate, 29 Democrats voted for the measure, including Kerry and Sens. John Edwards of North Carolina and Hillary Clinton of New York.
Kerry and Edwards, his running mate, have since reversed their stand and voiced opposition to the decision to go to war. Clinton has remained supportive of the president on Iraq.
"What we're hearing now is some politicians contradicting their own statements and making a play for political advantage in the middle of a war," Cheney said in his speech at the Frontiers of Freedom Institute's 2005 Ronald Reagan gala.
"The saddest part is that our people in uniform have been subjected to these cynical and pernicious falsehoods day in and day out," he said.
Kerry responded by saying that Cheney "continues to mislead America about how we got into Iraqi and what must be done to complete the still unaccomplished mission."